It's a feature.
Afraid you've been missing a lot of discussion, most probably that contained on BK's blog. With such fast moving development in this kennel, one has to read the lot. My problem is I tend to forget it after a week or so and cannot find it again!

Absolutely amazing on my 10yr old Acer laptop. Manual frugal to ext3, booting with grub4dos.
All seems very good OOTB - very snappy and low resource usage / temp.
Looks good, feels good and generally outstanding all round. Many thanks.

If you hold your mouse in the position shown below (and perhaps click and move slightly, maybe with a task open) you will likely be able to crash jwm. However the 701 developer snapshot now fixes this.This is in precise 5.5RC and other versions of puppy also.